Study On The Methods Of Dynamic Performance Evaluation Of High Speed Vehicles

High-speed railway in China has been developing rapidly for the last few years, and higher dynamic performance is required for the vehicles as the speed increases. How to raise vehicle running stability and improve ride comfort and curving performance is very important for the development of high-speed trains, among which the lateral stability, one of the key factors for safe operation, is paid high attention by researchers. Once the vehicle hunting motion appears, the quality of operation will be worsen sharply and the ride performance will be affected. Further, serious wheel/rail interaction may cause track or even derailment. Therefore, it is of great significance to evaluate the lateral stability of high-speed vehicles.The technologies of high-speed railways in China now are in the global leading positions. However, in order to become the real power for high speed railways, except to strengthening the basic research and raising of the technology innovating ability for high speed trains, we must establish an entire set of criterion and standard regulations for the design of high speed trains. While the evaluation standards for the dynamic performance of high speed trains, which are related to the comfortability, safety and reliability of high speed train operation, should be completed as soon as possible. Therefore, detailed research is conducted in this thesis in accordance with the evaluation problems of the dynamic performance of high speed vehicles.The nonlinear dynamic model of a high speed vehicle is set up by SIMPACK software. Three working conditions are determined in advance through changing the parameters of the anti-hunting dampers in order to conveniently analyzing the vehicle lateral stability at different speeds. By applying the limit cycle evaluation method, the corresponding hunting critical speeds for the three working conditions are calculated as 251,301,351km/h. Meanwhile, the methods of standard TSI L84 bogie frame acceleration amplitude, UIC515 bogie frame acceleration amplitude, bogie frame and wheelset acceleration RMS, sum of guiding forces RMS are used to evaluate the lateral stability of the vehicle system and the corresponding critical speeds are obtained. For the method of bogie frame acceleration amplitude regulated in standard TSI L84, it is suggested that the frequency filtering range 3-9Hz should be modified to 2-9Hz to cover the hunting frequencies lower than 3Hz in order to get more accurate evaluation results. Finally, the derailment safety and ride quality of the vehicle system after the loss of stability are investigated.The ride quality of high speed vehicle is evaluated by using the ride index, ride comfort and vibration acceleration methods, and the evaluation results are compared for different methods. The running safety is also evaluated by the indices of derailment coefficient, wheel load reduction, wheel/rail vertical and lateral forces.